Telephony.



No. 726,984. v PATENTBD MAY 5, 1903.

' W. E. PEMBLETON.

TELEPHONY.

. APPLIOATION FILED JUNE 19, 1901.

N0 MODEL. 7 I 2 sums-41mm 1.

No..726,98 1. PATENTED MAY 5,1903.

\ W. L PEMBLBTON.

TELEPHONY.

APPLICATION FILED JUNE 19, 1901 H0 MODEL. 2 SHEETS-SHEET 2L I v gjyyv e 01/ wewaw 33% I WW3 UNITED STATES Patented May 5, 1903.

. ATENT FICE.

TELEPHONY.

SPECIFICATION forming part of Letters Patent No. 726,984, datedrMay 5, 1903.

7 Application filed June 19, 190] Serial No. 65,095. (No model.)

To all whom it may concern;-

Be it known that I, WILLIAM E. PEMBLE- TON, a citizen of the United States, and a resident of Wittenberg, in the county of Shawano and State of Wisconsin, have invented certain new and useful Improvements in Telephony; and I do hereby declare that the following is a full, clear, and exact description thereof.

My invention has for its object to provide for secrecy in the matter of communication by telephone on party-lines, whether local or long distance, as well as to prevent switchboard operators from hearing conversation carried on through private-line telephones without knowledge of those conversing, said invention consisting in what is hereinafter particularly set forth with reference to the accompanying drawings and subsequently claimed.

Figure 1 of the drawings is a diagram illustrating my improved telephone apparatus at a subscribers station on a party-line; Fig. 2, a diagram illustrating means for connecting a party-line and switchboard; Fig. 3, a diagram illustrating a switchboard operators signaling and talking set.

Referring by letter to the drawings, A B indicate parallel conductors constituting the line of an electric-telephone system in which my improvements are embodied, particular reference being had to a party-line that may be either local or long distance. The partyline subscriber telephone illustrated in Fig. 7

contact 0 is electrically connected to conduc tor A, and contact 01 is normally in touch with a contact-point e, electrically connected to a magneto F or other current-generator in circuit with an electric signal G, (audible or otherwise,) the primary of an induction-coil H, and conductor B, the secondary of this coil and a resistance I in series therewith being permanently bridged between said condoctors. Lever O is also shown provided witha depending fi ngerf, that in its normal position prevents a spring-contact g from being moved into touch witha contact-point h,

a contact 2' under an extremity of the aforesaid tilt-hook lever parallel to other contacts 2" 71. Contact 11 is in electric connection-with the secondary of induction-coil M, and contact 2' has like connection with the aforesaid batteries. A spring-contactj is shownfast to the other extremity of lever O, opposed by a contact-point It, withwhich it is normally out of touch, this point being electrically connected to the secondary of induction-coil H and an electromagnet P, this magnet being likewise connected to the two batteries aforesaid. The armature of the electromagnet P is part of one arm of a bell-crank lever Q, and the other anm of thislever is made to constitute acatch for the tilt-hook lever O','abov'specifid; To limit play of lovers 0, O, andQ, stop-screws m are conveniently arrangedas herein shown, and a spring-contactn is arranged in electric connection with conductor A to be put in touch with contact (1 at will.

When the telephone-receiver D is taken off hook and leverC automatically tilted tohave its arm I) close the circuit in which contacts 0. d are placed, the contact dis lifted clear of contact-point c, with w'hi ch it is normally in touch. If the line is then in use, current therefrom will flow from cond u ctorB through electromagnet N, contact d, lever-arm b, and contact a to conductor A, the armature of said magnet being then attracted to thereby tilt lever O, and thus bring contactq'in touch with point In to close the circuit that includes electromagnet P, battery K, transmitter L,

and primary of induction-coil M, the armature of electromagnet P being attracted to tilt bell-crank lever Q and bring catch-arm of same under the adjacent end of the tilthook lever, thereby preventing the same from coming into touch with the contacts 1' 01 'i", the receiver of the telephone being thus cut out from the line to prevent overhearing. To ascertain if the line is busy without taking receiver'D off hook, the contact 'n may be put in touch with contact d to close circuit with the line by Way of electromagnet N, and if the armature of said magnet be attracted it is evident that said line'is in use.

If there be no current on the line when re- .ceiver D is taken off hook, the spring E will tilt lever 0 far enough to have its arm I) clear the contacts 0 (1, its fingerf being at the same time carried clear of contacts g h and one end of said lever brought into touch with contacts 11 t" t', thereby closing both primary and secondary circuits of the telephone. Battery J is now in circuit with conductor A, contact 1', lever 0, contact 11, secondary of induction-coil M, receiver D, and conductor B. 'Hence as there is current on the line none of the other telephones on said line can cut in; but if contact 9 be put in touch with point h said battery will be short-circuited for the time being to permitthe telephone that is called to cut in on the aforesaid line. The calling is done by operating generator B when contact dis in touch with contactpoint e, whereby a closed circuit is established through said generator, signal G, primary .of induction-coil H, and electromagnet N, there being induced current through the secondary of said coil and the resistance I, that are bridged between the conductors A B of the line. Magnet N being energized, its

armature is attracted and lever 0 brought into circuit with the secondary of inductioncoil H, cutting out the resistance I aforesaid. Calling-current being generated on the line at one telephone, it will flow through resistance I and secondary of induction-coil H of each other telephone on the party-line, in-

' ducing current in primary of said coil to thereby energize electromagnet N and attract its armature, the lever 0 being thus operated to close a circuit, as aforesaid, from which said resistance is eliminated, this resistance at each telephone being at all times as high as possible in proportion to the number of cells of the battery J aforesaid.

To connect party-lines, apparatus similar to that shown in Figs. 2 and 3 is employed at a switchboard-terminal of the lines in connection with the flexible cord of an operators signaling and talking set, this cord having plug-terminals engageable with jacks of the apparatus. One strand of the cord joins sleeves p, and the other strand joins pins (1, that extend through said sleeves beyond the same and are insulated therefrom, these sleeves and pins constituting the preferred form of plug-terminals for said cord. Each jack preferably consists of a longitudinallyslotted conductor-shell R, a s pring-contact r in connection therewith havingabend extending through the slot, and another spring-contact 3 forward of said shell electrically connected to conductor A, contact 1" being likewise connected to conductor B and opposed by a contact-point t, electrically connected to another spring-contact u, that closes on a contactpoint 1;, wired with said contact? to conductor B of the line. Contact-point iand contact u are put in circuit with a signal Gr, primary of an induction-coilH', a generator F, electromagnet N, and conductor A of the line, the secondary of said coil and resistance 1 being permanently bridged between both conductors of said line.

The armature of electromagnet N is part of a lever O, electrically connected to conductor A and another electromagnet P, that is likewise connected to a battery K, this battery being similarly connected to a contact-point w, opposed to said lever. Battery K is also electrically connected to resistance 1, in like connection with the secondary of induction-coil H, similarly connected to conductor B of the line. The armature of magnet P is one arm of a bell-crank lever Q, the other arm of which is oifset to come between shell R and contact 3 of the jack when said magnet is energized.

If the jack is plugged, the plug-sleeve p, acting on contact r, will force the same into touch with point t, and if there is current on the line the electromagnet N will attract armature-lever O, and thereby close the circuit containing the other electromagnet P, energizat-ion of this magnet operating to tilt armature-lever Q into position to serve as a barrier that prevents plug-pin g from coming into touch with contact 8 while said line is busy. To make busy test of the line without plugging the jack, the spring-contact u is put in touch with contact-point o to close the magnet-circuit, and if there be current on said line the armatu re-levers will be attracted, as above described.

The pin-strand of the flexible connectingcord is shown in circuit with a pair of contact-blades 5c, in touch with extremities of a conductor-bar 1 and the sleeve-strand of said cord is'shown connected to generator F, put in circuit with contact-points z in opposition to said blades, normally out of touch with the same. Spring-contacts b are also shown arranged to oppose the contact-blades 00, normally out of touch with the same, and a .L-lever S is arranged to swing between said blades and move either of them into touch with an adjacent spring-contact b and contact-point 5, thus closing a signal-circuit through the aforesaid cord.

The operators set is shown as including brushes T U, each comprising a series of flexible radially-disposed conductoi' sti'ips having insulation facings, these facings of one series of brush-strips being in a direction opposite those of the other series of similar strips. One conductor-strip in each brush is electrically connected to the bar y. Another of these strips in each brush is likewise connected to the secondary of an induction-coil V, put in circuit with the plugsleeve strand of the flexible cord aforesaid, the primary of this coil being in circuit with a battery W and transmitter X. Another conductor-strip in brush T is electrically connected to an audible electric signal Y, the corresponding strip in brush U being likewise connected to a similar signal Z, having a different tone from the one Y, both of these signals being adjacent to a transmitter X in circuit through the same with a battery W and primary of the induction-coil V aforesaid. A fourth strand 1) of brush U is electrically connected to the spring-contacts b aforesaid. The brushes are in the path of the operators lever A, and swing of this lever in one direction will cause contact of the same with insulation of one brush and the conductor-strips of the other brush, said lever being a circuit-closer in either direction of its throw. A spring-contact 0, also in the path of lever A in one direction of its swing, is electrically connected to the secondary of an induction-coil B and the flexible cord, the primary of the coil being in circuit with the transmitter L and local battery K of the operators telephone, the receiver D of this telephone and a battery J being electrically connected to said cord and a contact-point d opposed to said springcontact normally out of touch with same. By means of push-button mechanism shown at O the battery J may be short-circuited from the line to unlock the telephone of the called subscriber thereon, so that the one called may be cut in.

When lever A is swung from the position shown, it will touch on insulation of brush- U and the conductor-strips of brush-strips of brush T before it operates to force contact 0 into touch with point (1, and thus signal Y. will be energized to notify subscribers that the operators telephone has been cutin. Re-

' ver's'emoti on of the operators leverwillclose circuit with brush U to energize signal Z, and thus notify subscribers in communication that the operators telephone is cut out.

The strip 1) in brush U, wired to contacts I), prevents operator from opening one side of the plug-cord circuit with lever S and then cutting in without having the cut-in signal transmitted.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-- 1. In a party-line electric-telephone system, the combination of the spring-controlled tilthook lever constituting the receiver-hanger and closer for the normally open primary and secondary circuits of: each subscribers telephone, a catch arranged to be moved in the way of the circuit-closing portion of said lever, electric catch-operating mechanism in independent open circuit with the line of said system, and an arm of the aforesaid lever constituting a temporary closer for said independent circuit ahead of the closing of said other circuits; whereby in case of current on the line when the receiver of said telephone is taken off hook the catch will be actuated to prevent closing of the aforesaid primary and secondary circuits.

2. In a party-line electric-telephone system, the combination of an automatic current-generator in the primary circuit of each subscriber telephone, means constituting part of said telephone for automatically preventing cut in of same when there is current on the line, and other means for shortcircuiting said generator at will subsequent to a cut in of the aforesaid telephone to thereby temporarily divert current from said line to permit the cut inof another telephone called by the one aforesaid. V

3. Inaparty-line electric-telephonesystem, the conductors A, B, and subscribers telephones each comprising spring-controlled tilthook lever 0, having upper arm I), spring-contacts 0 din the path of the lever-arm, contactpoint 6 with which contact d is normally in touch, current-generator F electric signal Gr, induction-coil H resistance I, batteries J, K, transmitter L, induction-coil M, receiverD, electromagnet N, armature O, contactj, point It, electromagnetP, combined armature and catch Q and contacts '5, i, 2', all arranged and connected as herein set forth.

at. In a party-line electric-telephone system, the conductors A, B, and subscribers telephones each comprising spring controlled tilthook lever 0, having upper arm b, spring-contacts c, d, in the'path of the lever-arm, contactpoint 6 with which contact d is normally in touch, current generator F, electric signal G,

induction-coil H, resistance I, batteries J, K, transmitter L, induction-coil M, receiver D, electromagnet N, armature 0, contact j point It, electromagnet P, combined armature and catch Q, contacts 1', i, t', and contact at, all arranged and connected as herein set forth. g. In a party-line,electric-telephone system, the con'duTs'tors' "A; B; *and subscribers telephones each comprising spring controlled tilthook lever 0, having upper arm b, spring-contacts c, d, in the path of the lever-arm, contactpoint e with which contact (1 is normally in touch, current-generator F, electric signal G, induction-coil H, resistance I, batteries J, K, transmitter L induction-coil M, receiver D, electromagnet N, armature 0, contact j, point it, electromagnet P combined armature and catch Q, and contacts g, h, 2', 0,11, all arranged and connected as herein set forth.

6. In an electric-telephone system,a switchboard-terminal apparatus for independent party-lines comprising jack-shell R, contact r having a bend extending through a shellslot, contact 8, current-generator F, electric signal G, induction coil H, resistance 1, electromagnet N, armature O, contact-point w,battery K,e1ectromagnet P, and armaturelever Q, all arranged and connected as herein set forth, together with an operators connecting-cord, each plug-terminal of which comprises a sleeve and a pin that being in insulated engagement with the sleeve extends forward of the same.

7. In an electric-telephone system ,a switchboard-terminal apparatus for independent party-lines comprising an automatic currentgenerator in a calling-circuit, means constituting part of each subscriber telephone of said lines for preventing cut in of same when the aforesaid lines are connected and influenced by current from the generator, and other means for short-circuiting said generator at will.

8. In an electric-telephone system,a switchboard-terminal apparatus for independent party-lines comprising an electric signal and contacts 14, Q), in open-circuit connection with line conductors, and means for energizing the signal when the circuit is closed by said contacts.

9. In an electric-telephone system,a switchboard-terminal apparatus including an operators calling and talking set comprising a pair of radially-disposed brushes the flexible conductor strips of which have their free ends faced upon one side with insulation, the insulation facings in one brush being in a direction opposite those in the other; a plugcord and a strip of each brush electrically connected, an induction-coil having its secondary in circuit with said cord and another strip of each brush, an audible electric signal mechanism in circuit with the primary of said coil and a strip of each brush independent of the strips aforesaid, an operators circuitclosing lever arranged to be swung against said free ends of the brush-strips, and a talking-circuit closer opposed to the lever in'one direction of its throw.

10. In an electric telephone system, a switchboard-terminal apparatus including an operators calling and talking set comprising a pair of radially-disposed brushes the flexible conductor strips of which have their free ends faced upon one side with insulation, the insulation facings in one brush being in a direction opposite those in the other, a plugcord having a strand thereof interrupted by spring-contacts normally in touch with extremes of a conductor electrically connected to one of the strips in each brush, a currentgenerator Wired to contact-points opposed to the spring-contacts out of touch with same, a pivotal L-leverintermediate of said springcontacts, another pair of spring-contacts opposing those aforesaid out of touch with same and electrically connected to each other and a strip of one of the brushes, an induction-coil having its secondary in circuit with another strand of said cord and an independent strip of each brush, an audible electric signal mechanism in circuit with. the primary of said coil and another independent strip of each brush, an operators circuitclosing lever arranged to be swung against said free ends of the brush-strips, and atalk ing-circuit closer opposed to this lever in one direction of its throw.

In testimony that I claim the foregoing I have hereunto set my hand, at Wittenberg, in the county of Shawano and State of Wisconsin, in the presence of two witnesses.

WILLIAM E. PEMBLETON.

Witnesses:

H. MEISNER, O. F. DOLAN. 

